Question

What evidence did Sperry find that supports his chemoaffinity hypothesis? Have Sperry’s proposed “recognition molecules” been found?

Answer 1

The chemoaffinity hypothesis states that neurons makes connections with their targets based on interactions with specific molecular markers. The markers are generated during cellular differentiation and aid not only synaptogenisis but also acts as guidance cues for their respective axons.

Roger wolcott perry pioneered the inception of the chemoaffinity hypothesis followed by experiments on African clawed frog where he removed its eye and rotated it to 180degrees. Sperry then replaced the eye and the visual nervous system repaired itself. However the frog has inverted vision. When the food source was placed down front then the frog placed its tounge upwards. Sperry proposed that different cells bear distinct cell surface proteins that serve as markers. There is now extensive data that supports the chemoagffinity hypothesis but some aspects are unproven.